A lubricant composition comprising: a fully formulated commercial lubricating oil which comprises from 0.01 to 2.0 percent by weight of an oil soluble organo-molybdenum friction modifier and at least 0.1 percent by weight active sulfur of a surface active sulfur donor component is effective in preventing the removal of DLC coatings while at the same time allowing the beneficial friction-reducing effects from the molybdenum friction modifier to occur.
